I know this question is a couple of years old but we've done it twice now. Go outside the gate of the port and catch a cab to the municipal airport. We booked our flights online. We came back about 1.5 hours before the ship left. Rented a golf cart on AC and beach bar hopped. FUN! If you search my posts from a few years ago, you'll find my complete review of going over to AC for the day.